Striped Hyaena: Social Behavior

Almost invariably described as solitary in Africa, a recent study by Wagner (2006) in Kenya study found that striped hyaenas do frequently rest in pairs and occasionally in groups of up to four individuals. These groups never include more than one adult female.  Foraging is strictly solitary, beyond mothers with cubs, and even though a number of individuals may visit the same carcass to scavenge, they do not visit the sites at the same time.  Age specific foraging data is extremely limited, but cubs have been observed accompanying their mothers on foraging forays by 6-12 months of age (Kruuk 1976, Wagner pers. obs.).

Rieger (1979a, 1981) has argued that across subspecies, differences in body size, proportion of killed prey items in the diet, and group sizes (sociality) co-vary. The two smaller subspecies, H. h. dubbah and H. h. sultana, formerly sympatric with the spotted hyaena, are supposed to be more solitary and are not known to kill larger wild or domestic herbivores. The larger subspecies H. h. syriacaH. h. hyaena and H. h. barbara, however, kill larger herbivores and have been repeatedly observed in small groups. Current information is inadequate to test this data. 

Typical group sizes are one or two in all subspecies (Rieger 1979a), although groups of up to seven animals have been reported in H. h. dubbah in Libya (Hufnagi 1972). In Israel, H. h. syriaca is generally solitary, but occasionally several are seen together at a carcass, apparently males and females, or females and large cubs (Macdonald 1978). H. h. syriaca has been recorded as monogamous in central Asia (Heptner and Sludskij 1980). 

Home range sizes of one female and one male in the Serengeti were 44km2 and 72km2 respectively, with little evidence of territorial behaviour (Kruuk 1976). Van Aarde et al. (1988) calculated a home-range size for a single female in the Negev desert in Israel to be approximately 61km2 over a period of seven months, which partly overlapped with two other individuals. In Kenya, the mean home range sizes for 12 males was 82 km2 (SE=12) and for eight females was 71 km2 (SE=15) (Wagner pers. obs.), with no significant difference in home range sizes between sexes.  No two adult females were found to have significant home range overlaps, although groups of up to three males and one adult female had almost complete overlap in home ranges.

Figure (provided by Aaron P. Wagner) shows home range overlap between male and female striped hyenas

Very little has been recorded regarding direct social interactions outside of captive situations.  Kruuk (1976), did note the meeting ceremony between greeting pairs which involved mutual sniffing of the face, neck, and anal regions.  The anal pouch was protruded during sniffing and either both hyaenas were standing or one would lie down while exposing the anal region.  Observations in captivity (Rieger 1978) match these field observations and Fox (1971) observed anal protrusions displays in cubs at eight weeks of age.  The dorsal mane is also erected by striped hyaenas in a defensive posture and, when aggressive, both the mane and the tail hairs are erected (Rieger 1978).

When threatened, the long dorsal hairs may be erected (Schneider 1926, Kruuk 1976, Rieger 1978, Wagner pers. obs.).  The dark throat patch has thickened skin and denser fur (Harrison 1968).  This has been proposed as a mechanism to orient bites during agonistic interactions (Rieger 1978).  However, further observations from captivity and of bite marks in wild hyaenas indicate that bites are routinely directed at the back of the head and upper neck (Wagner 2007).

Large ducts from the anal glands open into an anal pouch dorsal to the anus.  The pouch is inverted during scent marking (pasting) and greeting behaviour (Holzapfel 1939, Fox 1968, Kruuk 1976, Rieger 1977, Rieger 1978).  The well developed anal pouch produces a pungent yellow to beige colored paste which is deposited on grass stems and/or sticks (Fox 1971, Kruuk 1976, Rieger 1981).  Rarely observed, it is unclear whether this behavior is used to mark territories, although it is presumed that this is the case.  Pasting has also been observed at large carcasses and, in captivity, on food bowls (Wagner 2006).

Photo courtesy of the Living Desert.

When striped hyaenas fight they bite at the throat and legs, not the mane. The mane serves as a signalling device during social interactions. During meetings, striped hyaenas investigate and lick the mid-back region where the mid-dorsal crest is situated. Greetings also involve sniffing of the nose and extruded anal pouch, and repeated pawing of the throat of the greeting partner (Fox 1971, Rieger 1978, Macdonald 1978). In aggressive encounters, the black patch near the thoracic and lumbar vertebrae is erected (Rieger 1979a). The striped hyaena scent marks (pastes) on grass stalks, stones, tree trunks and other objects, with secretions from the anal pouch (Kruuk 1976). The striped hyaena uses a smaller variety of calls than the spotted hyaena (Kruuk 1976, Peters 1984).

 Whining by cubs before suckling, giggling when frightened, yelling when being chased by conspecifics, lowing in a defensive position, growling when play or food-fighting, and a call by the mother to her cub(s), have all been recognized (Kruuk 1976, Rieger 1981, Wagner pers. obs.).  Striped hyaenas are considerably quieter than the spotted hyaena Crocuta crocuta, in terms of both volume and frequency of vocalizations, and are generally silent

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